Russia signalled on Monday it might ban Western airlines from flying over its territory as part of an “asymmetrical” response to new European Union sanctions over the Ukraine crisis.

Russia signalled on Monday it might ban Western airlines from flying over its territory as part of an “asymmetrical” response to new European Union sanctions over the Ukraine crisis.

Blaming the West for damaging the Russian economy by triggering “stupid” sanctions, Prime Minister Dmitry Medvedev said Moscow would press on with measures to reduce reliance on imports, starting with increasing output of domestic aircraft.

Medvedev suggested Russia should have hit back harder over the action by the United States and European Union to punish Moscow for its role in Ukraine, saying it had been too patient in the worst confrontation with the West since the Cold War.

“If there are sanctions related to the energy sector, or further restrictions on Russia’s financial sector, we will have to respond asymmetrically,” he told Russian daily Vedomosti, adding the airlines of “friendly countries” were allowed to fly over Russia.

“If Western carriers have to bypass our airspace, this could drive many struggling airlines into bankruptcy. This is not the way to go. We just hope our partners realise this at some point,” he said in the interview published on Monday.

After suggesting it would hold off imposing new sanctions to give Moscow time to show it was resolving the Ukraine conflict, the European Union said on Monday it would press ahead with implementing the new measures later in the day.

An EU diplomat said Russia’s top oil producers and pipeline operators Rosneft, Transneft and Gazprom Neft were on its list of state-owned firms that would not be allowed to raise capital or borrow on European markets.

A shaky ceasefire agreed on Friday in Ukraine has done little to convince some Western countries that Russia is committed to resolving the conflict in the country’s east which has killed more than 3,000 people.